State's earthquake-warning system edges closer to reality

A USGS ShakeAlert earthquake early-warning system map shows the location, earthquake intensity and seconds until seismic waves are expected to hit a particular location. Courtesy of U.S. Geological Survey.

California Gov. Jerry Brown's approval of earthquake-warning legislation on last week, will bring development of a statewide early-warning system closer to reality.

Brown signed Senate Bill 438 on Thursday, Sept. 29, which was introduced by State Sen. Jerry Hill, D-San Mateo. The law established the California Earthquake Early Warning Program and Advisory Board within the California Governor's Office of Emergency Services (Cal OES) to advance the program and promote further investment in the early-warning system, which has been in testing since 2012.

Previous state estimates pegged the cost of making the system public at $54 million.

Under the legislation, a business plan would be developed for the early-warning system that will be submitted to the state Legislature by Feb. 1, 2018.

"We've seen the devastation earthquakes have caused in California," Brown said. "This keeps us on track to build a statewide warning system that can potentially save lives."

The legislation builds on further bills Brown has signed into law related to developing the system. In 2013, he signed SB 135, introduced by then-state Senator Alex Padilla, which mandated creating a statewide earthquake-warning system, and was to be led by Cal OES and organizations from the California Integrated Seismic Network, the private sector and all levels of government.

Earlier this year, Brown directed $10 million to Cal OES in the 2016-17 state budget to expand the state's earthquake early-warning system prototype, called ShakeAlert. That system has been tested since 2012 with public agencies and private businesses, including Bay Area Rapid Transit (BART), Metrolink, Google and Cal OES.

ShakeAlert has predicted earthquakes within four to five seconds of the initial seismic waves, according to U.S. Geological Survey scientists. Using the California Integrated Seismic Network, an existing series of 400 high-quality ground-motion sensors positioned six to 12 miles apart, the system sends sensor information to distribution centers, which transmit a warning to people after detection of the initial seismic waves. The program also warns of the expected level of the shake's intensity, which is different from the quake's magnitude at the epicenter.

Earthquake early-warning systems are currently in place in Mexico and China. Other countries throughout the world are in the process of developing early-warning systems, according to the Brown's office.

Hill, who introduced the latest legislation, said the early earthquake-warning system would help save lives.

"In emergencies, every second counts and the urgent alerts that will be sent by the warning system can help prevent devastating and life-threatening missteps," he said in a joint statement with Brown's office.